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Anonymous301
Joined: Dec 25, 2015 Posts: 4 Location: Germany
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Posted: Thu Oct 10, 2019 10:28 am Post subject:
AS3330 behaving strange :/ |
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Hey,
I'm currently trying to build a VCA with an AS3330. I build one of the VCAs according to the datasheet. As i powered the circuit, i saw, that the output signal was weaker as i expected and that this annoying high frequency noise in it.(ass seen on the image). Input was a 5V AC-coupled sawtooth.
I tried multiple things: adding a filter to pin 7 like in the original CEM3330 Datasheet, tying the inputs of the other VCA to ground with resistors, adding many capacitors on the supply.(as seen on the image) But all of this didn't work.
Does anyone have an idea?
Best regards,
Franz
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Last edited by Anonymous301 on Sun Oct 20, 2019 12:15 pm; edited 1 time in total |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Thu Oct 10, 2019 2:39 pm Post subject:
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Did you use a proper ground for your scope? _________________ my synth |
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Electric Druid
Joined: Mar 13, 2012 Posts: 44 Location: UK
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Posted: Fri Oct 11, 2019 11:59 am Post subject:
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Grumble wrote: | Did you use a proper ground for your scope? |
That was my first thought too. Looks like bad grounding, which happens a lot on breadboard circuits with scope probes flying about all over the place. _________________ Electric Druid Synth and Pedal DIY website |
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Anonymous301
Joined: Dec 25, 2015 Posts: 4 Location: Germany
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cslammy
Joined: Apr 27, 2018 Posts: 206 Location: USA
Audio files: 1
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Posted: Mon Oct 14, 2019 7:02 am Post subject:
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Total guess: if you stripboarded or created a PCB your issue might go away?
I frequently have trouble with grounding, unwanted resistance, cap coupling that doesn't quite work, etc., on breadboards. Maybe because until recently I used a $3 banggood breadboard?
An EE told me when breadboarding always buy a really good bread board (3M for instance, which is expensive) even though I'm tempted to buy the cheapest thing I can find. He says: If the part isn't really nailed in there, and the cheap ones are a bit loosey goosey, you can have all sorts of issues. The 3M ones tend to have more positive contacts.
I did this and have had somewhat better results. Of course this could not be your issue at all..... _________________ Visit my AUDIODIWHY blog and website |
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JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
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Posted: Mon Oct 14, 2019 8:46 am Post subject:
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+1 on what cslammy said. I spent some cash on a breadboard system and it was well worth it.
Quality of the breadboard is important, but also pay attention to the conductors you insert. I've had parts not work or not work correctly due to dirt, grease, oil or corrosion on pins or leads. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
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Anonymous301
Joined: Dec 25, 2015 Posts: 4 Location: Germany
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Posted: Sun Oct 20, 2019 12:41 pm Post subject:
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Sorry for replying late, im finally back home
cslammy wrote: | Total guess: if you stripboarded or created a PCB your issue might go away? |
This sounds pretty logical to me, since the circuit worked for 5 minutes but then gave up again. And my breadboard is indeed a pretty cheap one, thats for sure.
I just finished a PCB Design utilizing the AS3330 and two AS3310s, i might get them done until next week.
Best regards,
Franz |
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